EXPLORATION OF ALASKA. 229 
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yellowish, of a length of about 0.045 mm., with a median furrow 
along the upper side and with thickened margins. The large laterals 
horn-yellow in color, reaching the height of about 0.1 mm. (PI. IX, 
fig. 170; Pl. X, fig. 2aa), hook-shaped, with a strong, rounded prom- 
inence at the inside of the root of the hook (fig. 17). On each side 
(Pl. X, fig. 26, ec) of the two large plates (in two individuals) con- 
stantly fifteen smaller, nearly colorless plates of a length of about 
0.06 mm. These plates were all somewhat depressed ; the five inner 
ones smaller, somewhat compressed (fig. 2, 3a, 15); the others (fig. 2, 3) 
broader, with the upper edge broad and irregularly toothed ; the outer- 
most (fig. 2c) a little smaller than the adjoining plates. The bases in 
each of these (fifteen) plates large, forming nearly half, or at least 
making more than a third of the size of the whole plate.! The crop 
of the bulbus of the usual form, as large or a little larger than the bulbus 
itself; with a very short stalk with strong longitudinal musculature, 
its aperture opening immediately behind the lip-disk. 
The salivary glands large, white, very elongate, in their foremost 
part broader, and with several coils filling the space left between the 
crop, the bulbus and the cesophagus. 
The esophagus long. The stomach small, enclosed in the liver; 
the intestine rather short, forming its knee behind the fore-end of the 
liver. ‘The large posterior visceral mass about 9.0 mm. long by a 
breadth of 4.3 and a height of 3.5 mm. ; the posterior end somewhat 
pointed, though rounded ; the fore-end broader, perpendicular, somewhat , 
flattened on the right side; the color of the surface (hermaphroditic 
gland) ash-gray, the interior (the liver) brown or black brown, or 
quite yellow. 
The heart as usual. The sanguineous gland irregularly reniform, 
situated somewhat more towards the left side, rather thick, whitish, 
covering the central nervous system and a large part of the bulbus 
pharyngeus from above. The renal syrinx as usual. 
The hermaphroditie gland without developed sexual elements. The 
anterior genital mass proper rather small, compressed, of about 2.5 mm. 
largest diameter, but the loop of the spermatoduct (and the penis) 
nearly as large as the rest of the mass. The spermatoduct long, 
in its first part white, rather strong; nearly as long as the second in 
which it passes through a stricture; this last part is thicker, cylindrical, 
elongated, about 5.0 mm. long, passing without exact limits into the 
' In both individuals the three to five foremost rows were without the 
smaller plates, and the following two or three very incomplete in this respect. 
